pmem, dax: have direct_access use __pmem annotation

Update the annotation for the kaddr pointer returned by direct_access()
so that it is a __pmem pointer.  This is consistent with the PMEM driver
and with how this direct_access() pointer is used in the DAX code.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/fs/dax.c b/fs/dax.c
index e07fecc..7c634ac 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -35,7 +35,7 @@
 
 	might_sleep();
 	do {
-		void *addr;
+		void __pmem *addr;
 		unsigned long pfn;
 		long count;
 
@@ -47,7 +47,7 @@
 			unsigned pgsz = PAGE_SIZE - offset_in_page(addr);
 			if (pgsz > count)
 				pgsz = count;
-			clear_pmem((void __pmem *)addr, pgsz);
+			clear_pmem(addr, pgsz);
 			addr += pgsz;
 			size -= pgsz;
 			count -= pgsz;
@@ -62,7 +62,8 @@
 }
 EXPORT_SYMBOL_GPL(dax_clear_blocks);
 
-static long dax_get_addr(struct buffer_head *bh, void **addr, unsigned blkbits)
+static long dax_get_addr(struct buffer_head *bh, void __pmem **addr,
+		unsigned blkbits)
 {
 	unsigned long pfn;
 	sector_t sector = bh->b_blocknr << (blkbits - 9);
@@ -70,15 +71,15 @@
 }
 
 /* the clear_pmem() calls are ordered by a wmb_pmem() in the caller */
-static void dax_new_buf(void *addr, unsigned size, unsigned first, loff_t pos,
-			loff_t end)
+static void dax_new_buf(void __pmem *addr, unsigned size, unsigned first,
+		loff_t pos, loff_t end)
 {
 	loff_t final = end - pos + first; /* The final byte of the buffer */
 
 	if (first > 0)
-		clear_pmem((void __pmem *)addr, first);
+		clear_pmem(addr, first);
 	if (final < size)
-		clear_pmem((void __pmem *)addr + final, size - final);
+		clear_pmem(addr + final, size - final);
 }
 
 static bool buffer_written(struct buffer_head *bh)
@@ -106,7 +107,7 @@
 	loff_t pos = start;
 	loff_t max = start;
 	loff_t bh_max = start;
-	void *addr;
+	void __pmem *addr;
 	bool hole = false;
 	bool need_wmb = false;
 
@@ -158,11 +159,11 @@
 		}
 
 		if (iov_iter_rw(iter) == WRITE) {
-			len = copy_from_iter_pmem((void __pmem *)addr,
-					max - pos, iter);
+			len = copy_from_iter_pmem(addr, max - pos, iter);
 			need_wmb = true;
 		} else if (!hole)
-			len = copy_to_iter(addr, max - pos, iter);
+			len = copy_to_iter((void __force *)addr, max - pos,
+					iter);
 		else
 			len = iov_iter_zero(max - pos, iter);
 
@@ -268,11 +269,13 @@
 static int copy_user_bh(struct page *to, struct buffer_head *bh,
 			unsigned blkbits, unsigned long vaddr)
 {
-	void *vfrom, *vto;
+	void __pmem *vfrom;
+	void *vto;
+
 	if (dax_get_addr(bh, &vfrom, blkbits) < 0)
 		return -EIO;
 	vto = kmap_atomic(to);
-	copy_user_page(vto, vfrom, vaddr, to);
+	copy_user_page(vto, (void __force *)vfrom, vaddr, to);
 	kunmap_atomic(vto);
 	return 0;
 }
@@ -283,7 +286,7 @@
 	struct address_space *mapping = inode->i_mapping;
 	sector_t sector = bh->b_blocknr << (inode->i_blkbits - 9);
 	unsigned long vaddr = (unsigned long)vmf->virtual_address;
-	void *addr;
+	void __pmem *addr;
 	unsigned long pfn;
 	pgoff_t size;
 	int error;
@@ -312,7 +315,7 @@
 	}
 
 	if (buffer_unwritten(bh) || buffer_new(bh)) {
-		clear_pmem((void __pmem *)addr, PAGE_SIZE);
+		clear_pmem(addr, PAGE_SIZE);
 		wmb_pmem();
 	}
 
@@ -548,11 +551,11 @@
 	if (err < 0)
 		return err;
 	if (buffer_written(&bh)) {
-		void *addr;
+		void __pmem *addr;
 		err = dax_get_addr(&bh, &addr, inode->i_blkbits);
 		if (err < 0)
 			return err;
-		clear_pmem((void __pmem *)addr + offset, length);
+		clear_pmem(addr + offset, length);
 		wmb_pmem();
 	}